The novel HLA-DPB1*05:01:20 allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-DPB1*05:01:20 differs from HLA-DPB1*05:01:01:01 by one nucleotide in exon 3.

The effect of acidity on the physicochemical properties of two hydraulic calcium silicate-based cements and two calcium phosphate silicate-based cements.

BACKGROUND: Bioceramic cements have been widely used in endodontic treatment. This study aimed to compare the microhardness, elastic modulus, internal microstructure and chemical compositions of Biodentine, WMTA, ERRM Putty, iRoot FS and IRM after exposure to PBS, butyric acid, and butyric acid followed by PBS. METHODS: Specimens of each material were prepared and randomly divided into 5 subgroups (n = 5): subgroup A: PBS (pH = 7.4) for 4 days, subgroup B: PBS (pH = 7.4) for 14 days, subgroup C: butyric acid (pH = 5.4) for 4 days, subgroup D: butyric acid (pH = 5.4) for 14 days, subgroup E: butyric acid for 4 days followed by 10 days in contact with PBS. The surface microhardness, elastic modulus, internal morphologic and chemical compositions of specimens were analyzed. RESULTS: The microhardness and elastic modulus values of all materials were significantly higher in the presence of PBS compared to exposure to butyric acid, with the same setting time (P < 0.01). After 4-day exposure to butyric acid followed by 10-day exposure to PBS, the microhardness values returned to the same level as 4-day exposure to PBS (P > 0.05). Biodentine showed significantly higher microhardness and elastic modulus values than other materials, while IRM displayed the lowest (P < 0.01). CONCLUSION: Biodentine seems the most suitable bioceramic cements when applied to an infected area with acidic pH. Further storage at neutral pH, e.g. PBS reverses the adverse effects on bioceramic cements caused by a low pH environment.

Predicting the Activity of Oral Lichen Planus with Glycolysis-related Molecules: A Scikit-learn-based Function.

OBJECTIVE: Oral lichen planus (OLP) is one of the most common oral mucosa diseases, and is mainly mediated by T lymphocytes. The metabolic reprogramming of activated T cells has been shown to transform from oxidative phosphorylation to aerobic glycolysis. The present study investigated the serum levels of glycolysis-related molecules (lactate dehydrogenase, LDH; pyruvic acid, PA; lactic acid, LAC) in OLP, and the correlation with OLP activity was assessed using the reticular, atrophic and erosive lesion (RAE) scoring system. METHODS: Univariate and multivariate linear regression functions based on scikit-learn were designed to predict the RAE scores in OLP patients, and the performance of these two machine learning functions was compared. RESULTS: The results revealed that the serum levels of PA and LAC were upregulated in erosive OLP (EOLP) patients, when compared to healthy volunteers. Furthermore, the LDH and LAC levels were significantly higher in the EOLP group than in the nonerosive OLP (NEOLP) group. All glycolysis-related molecules were positively correlated to the RAE scores. Among these, LAC had a strong correlation. The univariate function that involved the LAC level and the multivariate function that involved all glycolysis-related molecules presented comparable prediction accuracy and stability, but the latter was more time-consuming. CONCLUSION: It can be concluded that the serum LAC level can be a user-friendly biomarker to monitor the OLP activity, based on the univariate function developed in the present study. The intervention of the glycolytic pathway may provide a potential therapeutic strategy.

Effects of pre-mixed hydraulic calcium silicate putties on osteogenic differentiation of human dental pulp stem cells in vitro.

OBJECTIVES: An experimental tricalcium silicate and dicalcium silicate-containing endodontic putty has been designed to overcome the issue of reduced shelf life after exposure to atmospheric moisture during repeated opening of the container for clinical retrieval. The present study examined the effects of this experimental hydraulic putty on the mineralogenic characteristics of osteogenic lineage-committed human dental pulp stem cells (hDPSCs), by comparing the cellular responses with a commercially available putty (EndoSequence BC RRM Putty). METHODS: The osteogenic potential of hDPSCs that had been exposed to the putties was examined using quantitative reverse-transcription polymerase chain reaction for osteogenic gene expressions and western blot for osteogenic protein expressions. Alkaline phosphatase activity assay and alizarin red S staining were performed to detect changes in production of the intracellular enzyme and extracellular matrix mineralization respectively. RESULTS: Osteogenic differentiation of the hDPSCs was significantly enhanced after exposure to the pre-mixed hydraulic putties, with no significant difference between these two examined putties. CONCLUSIONS: The experimental hydraulic tricalcium silicate putty enhances osteogenic differentiation of hDPSCs to the same extent as a commercially available tricalcium silicate putty. CLINICAL SIGNIFICANCE: The experimental hydraulic putty appears to be an alternative to the commercial putty when used for applications involving the regeneration of bone in endodontics. Animal models are required for validating its potential in enhancing osteogenesis in vivo.

Manoeuvrability and biocompatibility of endodontic tricalcium silicate-based putties.

OBJECTIVES: The present study evaluated the indentation depth, storage modulus and biocompatibility of an experimental endodontic putty designed for endodontic perforation repair and direct pulp-capping (NeoPutty). The results were compared with the properties associated with the commercially available EndoSequence BC RRM Putty (ES Putty). METHODS: Indentation depth was measured by a profilometer following indentation with the 1/4 lb Gilmore needle. Elastic modulus was evaluated using a strain-controlled rheometer. The effects of eluents derived from these two putties were examined on the viability and proliferation of human dental pulp stem cells (hDPSCs) and human periodontal ligament fibroblasts (hPDLFs), before (1 st testing cycle) and after complete setting (2nd testing cycle). RESULTS: The ES Putty became more difficult to ident and acquired a larger storage modulus after exposure to atmospheric moisture. Biocompatibility results indicated that both putties were relatively more cytotoxic than the bioinert Teflon negative control, but much less cytotoxic than the zinc oxide-eugenol cement negative control. NeoPutty was less cytotoxic than ES putty in the 1st testing cycle, particularly with hDPSCs. Both putties exhibited more favourable cytotoxicity profiles after complete setting. CONCLUSIONS: NeoPutty has a better window of maneuverability after exposure to atmospheric moisture. From an in vitro cytotoxicity perspective, the NeoPutty may be considered more biocompatible than ES putty. CLINICAL SIGNIFICANCE: The experimental NeoPutty is biocompatible and is capable of reducing the frustration of shortened shelf life when jar-stored endodontic putties are exposed to atmospheric moisture during repeated opening of the lid for clinical retrieval.

Comparison of the use of d-enantiomeric and l-enantiomeric antimicrobial peptides incorporated in a calcium-chelating irrigant against Enterococcus faecalis root canal wall biofilms.

OBJECTIVES: To compare the anti-biofilm efficacy of two antimicrobial peptides (AMPs), 1018 and DJK-5, in disrupting canal wall biofilms in the isthmus, canal and dentinal tubules of single-rooted maxillary premolars. METHODS: Enterococcus faecalis single-species biofilms were formed in-situ in the root canal system of the premolars (n = 91). Confocal laser scanning microscopy, bacterial sampling, colony-forming unit counting, XTT assay, lactate dehydrogenase assay and phenol-sulphuric acid method were used to identify the anti-biofilm efficacy of both AMPs and their influence on bacterial metabolic activity. RESULTS: Both AMPs disrupted in-situ E. faecalis biofilms and altered their metabolic activity. At 20 µg/mL, the d-enantiomeric AMP DJK-5 killed 55.5 %, 57.3 % and 55.8 % of biofilm bacteria in the isthmus, canal and dentinal tubules, respectively, in 1 min. In contrast, the l-enantiomeric AMP 1018 only eradicated 25.6 %, 25.5 % and 27.5 % of biofilm bacteria in the isthmus, canal and dentinal tubules, respectively, within the same time. Anti-biofilm efficacy of the root canal irrigants tested were in the order: 6 % NaOCl > 20 µg/mL DJK-5 > 10 µg/mL DJK-5 > 20 µg/mL 1018 > 10 µg/mL 1018 > 0.9 % NaCl. CONCLUSIONS: The present results are confirmatory of previous studies, in that d-enantiomeric AMPs exhibit more potent antibacterial properties than l-enantiomeric AMPs against E. faecalis biofilms within the canal space. Nevertheless, the potency of both AMPs are concentration-dependent. Incorporation of these agents into EDTA, a non-antibacterial calcium-chelating irrigant for removal of the inorganic component of the canal space debris, does not reduce the efficacy of either AMP. CLINICAL SIGNIFICANCE: The present study provides the proof of concept that incorporation of an antimicrobial peptide into a calcium-chelating root canal irrigant enhances the disinfection of intratubular single-species biofilms during smear layer and smear plug removal.

Anti-biofilm efficacy of root canal irrigants against in-situ Enterococcus faecalis biofilms in root canals, isthmuses and dentinal tubules.

OBJECTIVE: To investigate the anti-biofilm efficacy of root canal irrigants in canal spaces, isthmi and dentinal tubules of root canals ex vivo. METHODS: Fifty-one single-rooted premolars, each containing an isthmus, were instrumented, autoclaved and inoculated with Enterococcus faecalis for 4 weeks. One specimen was sectioned for bacteria-specific staining to confirm the presence of biofilms using light microscopiy. The remaining specimens were randomly divided to five groups: (1) 0.9% NaCl, (2) SilverSol/H2O2, (3) HYBENX, (4) QMix 2 in1, (5) 6% NaOCl. Bacterial sampling was performed before (S1) and after (S2) canal irrigation. Diluted bacteria suspension was cultured for 48 h for counting the colony forming units (CFU). Percentages of dead bacteria and biofilm thickness were evaluated by confocal laser scanning microscopy (CLSM). Metabolic activity, lactic acid and polysaccharide synthesis of E. faecalis derived from S2 samples were analysed. RESULTS: The percentages of dead bacteria were significantly affected by the factor "irrigant" (p < 0.001) and the factor "location" (p = 0.017). The percentages of dead bacteria in the isthmi and canals were both in the ordor: NaCl < SilverSol/H2O2 < HYBENX < QMix 2 in1 < NaOCl (p < 0.05). Only 6% NaOCl disrupted biofilms and significantly reduced their thickness. The CFU, metabolic activity, polysaccharide and lactic acid production of E. faecalis were all reduced by the disinfecting solutions. CONCLUSIONS: SilverSol/H2O2 and HYBENX were less adept than QMix 2 in1 at killing biofilm bacteria in root canals. None of these antibacterial irrigants were effective, compared with 6% NaOCl, in disrupting biofilms. CLINICAL SIGNIFICANCE: There is advantage in using HYBENX or QMix 2 in1 to kill intratubular bacteria biofilms because of their capability in removing the inorganic component of the smear layer. SilverSol/H2O2 requires extra time to eradicate intratubular biofilms upon removal of the organic and inorganic components of the smear layer by other root canal irrigants.

Effect of SrtA on Interspecies Adherence of Oral Bacteria.

This study aimed to study whether the Sortase A (srtA) gene helps mediate coaggregation and co-adherence between Streptococcus mutans (S. mutans) and other salivary bacteria. S. mutans UA159 and srtA-deficient mutant served as "bait" in classical co-aggregation assays and membrane-based co-adherence assays were used to examine interactions of S. mutans with Fusobacterium nucleatum (F. nucleatum), Streptococcus mitis (S. mitis), Streptococcus gordonii (S. gordonii), Streptococcus sanguis (S. sanguis), Actinomyces naeslundii (A. naeslundii) and Lactobacillus. Co-adherence assays were also performed using unfractionated saliva from healthy individuals. Co-adhering partners of S. mutans were sensitively detected using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Both UA159 and its srtA-deficient mutant bound to F. nucleatum but not to any of the other five salivary bacteria. The srtA-deficient mutant showed lower co-adherence with F.nucleatum. The two S. mutans strains also showed similar co-adherence profiles against unfractionated salivary bacteria, except that UA159 S. mutans but not the srtA-deficient bound to a Neisseria sp. under the same conditions. Deleting srtA reduces the ability of S. mutans to bind to F.nucleatum, but it does not appear to significantly affect the binding profile of S. mutans to bulk salivary bacteria.

Erratum to: Effect of SrtA on Interspecies Adherence of Oral Bacteria.

The original version of this article unfortunately contained a mistake. One grant number is missing. The corrected one is given below.*This project was supported by grants from the National Natural Science Foundation of China (No. 81570974 and No. 81641035) and the Key Project of the Science and Technology Department of Sichuan Province (No. 2015JY0260).

A novel method in the removal of impacted mandibular third molar: buccal drainage.

Food impaction after impacted mandibular third molar extraction is a serious problem that should not be ignored. Incomplete suturing of the distal incision in the conventional method is the main cause of food impaction and delayed wound healing. The present study introduces a novel suture and drainage technology that requires hermetic suturing of the distal incision and rubber drainage for buccal drainage. 76 patients with horizontally/mesially impacted third molars (bilateral) were enrolled in this prospective study. An impacted tooth on one side of each patient was extracted by occlusal drainage using the conventional method, whereas the other side tooth was extracted by buccal drainage using the novel method. The differences in wound healing, facial swelling, bleeding and dry socket between the two sides of each patient were compared postoperatively, and the trends for patient selection of the surgical method were also compared. The results indicated that buccal drainage had obvious advantages in wound healing and reduced the risk of postoperative bleeding, and most patients preferred this technique; there were no significant differences in postoperative facial swelling or pain. Thus, buccal drainage can solve the problem of long-term food impaction induced by traditional incision postoperatively and is worthy of clinical promotion.

A micro-computed tomography study of the negotiation and anatomical feature in apical root canal of mandibular molars.

The aim of this study was to investigate the clinical negotiation of various apical anatomic features of the mandibular first molars in a Chinese population using micro-computed tomography (micro-CT). A total of 152 mandibular first molars were scanned with micro-CT at 30 µm resolution. The apical 5 mm of root canal (ARC) was reconstructed three dimensionally and classified. Subsequently, the access cavity was prepared with the ARC anatomy blinded to the operator. The ARC was negotiated with a size 10 K file with or without precurve. Information on the ability to obtain a reproducible glide path was recorded. The anatomical classification of ARC was Type I with 68.45% in mandibular first molars. The negotiation result of ARC with Category i was 387 canals (74.00%). With a bent negotiating file, 96 canals were negotiated, including 88 reproducible glide paths (Category ii) and 8 irregular glide paths (Category iii). About 7.65% canals could not be negotiated with patency successfully (Category iv). The statistical analyze shown the anatomic feature of ARC had effect on the negotiation of ARC (p < 0.05). In conclusion, ARC anatomic variations had a strong potential impact on the negotiation. The category of negotiation in ARC would be helpful in the using of NiTi rotary instruments. Negotiation of ARC to the working length with patency should be careful and skillful because of the complexities of ARC. SCANNING 38:819-824, 2016. © 2016 Wiley Periodicals, Inc.

MicroRNA-155-IFN-γ Feedback Loop in CD4(+)T Cells of Erosive type Oral Lichen Planus.

Oral lichen planus (OLP) is a T cell-mediated immune disorder, and we have indicated a Th1-dominated immune response in OLP. MicroRNA-155 (miR-155) could promote Th1 cells polarization. The present study aims to determine the role of miR-155 in immune response of OLP. The expression of miR-155 and the target mRNA was tested by Real-Time PCR. The serum levels of IL-2, 4, 10 and IFN-γ were examined with ELISA. Furthermore, in vitro study was built to observe the function of miR-155 in erosive-type OLP (EOLP). Finally, we determined the expression and correlation of miR-155 and SOCS1 in EOLP CD4(+) T cells. The results showed miR-155 was high related with the disease severities. Besides, serum IFN-γ was specifically increased in EOLP group, while IL-4 was decreased. In vitro studies showed miR-155 could reinforce IFN-γ signal transducer, and the induction of IFN-γ could also promote miR-155 expression in EOLP CD4(+) T cells. In addition, miR-155 levels were negatively related with SOCS1 mRNA expression in EOLP CD4(+) T cells. Our study revealed a positive miR-155- IFN-γ feedback loop in EOLP CD4(+) T cell, which might contribute to the Th1-dominated immune response. Furthermore, miR-155 could be used for the evaluation and treatment of OLP.

Calcium hydroxide removal in curved root canals with apical transportation In Vitro.

Calcium hydroxide (CH) is applied to improve disinfection of root canals in most root canal retreatment. This study aimed to analyze the CH removal efficacy using 7 different root preparing files (K file, pre-curved K file, EndoActivator, Ultrasonic file, pre-curved ultrasonic file, F file and needle irrigation alone) with apical transportation. Standardized models of curved canal with such apical transportation or not were set up before applying CH to root canal for 7 days. Seven techniques described above were used for its removal. Then the roots were disassembled and digital photos were taken. The ratio of residual CH in the overall canal surface was calculated using the image analyzer image pro plus 6.0. The data were analyzed using one-way ANOVA with post hoc Tukey test. Results revealed that CH was effectively removed (P<0.05) by using all 6 mechanical methods except irrigation alone. In curved root canals with apical transportation, EndoActivator, pre-curved ultrasonic file and F file were found to be more effective in removing CH than the other four file (P<0.001), while there was no significant difference among EndoActivator, pre-curved ultrasonic file and F file groups (P>0.05). The percentage of residual CH in the canal with apical transportation was higher than that in the canal without apical transportation (P<0.05). In conclusion, CH can be hardly removed completely. Canal with apical transportation will result in insufficient CH removal. EndoActivator, pre-curved ultrasonic file and F file are more effective in the curved root canal with apical transportation.

Quantitative comparison of calcium hydroxide removal by EndoActivator, ultrasonic and ProTaper file agitation techniques: an in vitro study.

Calcium hydroxide (CH) dressing residues can compromise endodontic sealing. This study aimed to evaluate the amount of remaining CH in root canals after mechanical removal by four groups of irrigation techniques including needle irrigation only, ProTaper file, EndoActivator, and ultrasonic file. Fifteen extracted single-rooted teeth were collected and used for all four groups. The samples were firstly prepared by ProTaper rotary instruments, and then sectioned longitudinally through the long axis of the root canals, followed by final reassembling by wires. CH was kept in the canals for 7 days setting. The removal procedure began with 5 mL of 2.5% sodium hypochlorite (NaOCl) followed by 1 mL of 17% ethylenediaminetetraacetic acid and a final irrigation with 5 mL of 2.5% NaOCl solution for all groups. No additional agitation of the irrigant was performed in group 1, while agitation for 20 s between irrigants was done with F2 ProTaper rotary file in group 2, EndoActivator with tip size 25/.04 in group 3 and by an ultrasonic file 25/.02 in group 4. The total activation time was 60 s. The roots were then disassembled and captured by digital camera. The ratio of CH coated surface area to the surface area of the whole canal as well as each third of the canal was calculated. The data were statistically analyzed by one-way ANOVA using post hoc Tukey test. Results showed that none of the four techniques could remove all CH. No significant difference was found between EndoActivator and ultrasonic techniques. However, they both removed significantly more CH than ProTaper and needle irrigation (P=0.0001). In conclusion, the sonic and ultrasonic agitation techniques were more effective in removing intracanal medicaments than the ProTaper rotary file and needle irrigation in all thirds of the canal.